FIFO worker guilty of murdering love rival

A West Australian fly-in fly-out worker has been found guilty, for a second time, of murdering a man who had a threesome with his girlfriend while he was away.

Ryan Christopher Hawke, 36, has been on trial in the WA Supreme Court for the past fortnight, accused of repeatedly stabbing Mark Colin Koller, 50, at the Crystal Brook Caravan Park in Orange Grove in April 2014.

The court heard Hawke found out his girlfriend had engaged in a threesome with Mr Koller and his partner, and stabbed the victim six times with a knife during a confrontation outside Mr Koller's caravan.

"He was very annoyed someone had done this with his woman," Prosecutor Sean O'Sullivan said during his opening address.

Hawke had argued self-defence, with his lawyer Justine Fisher saying some witnesses described Mr Koller as being the aggressor.

The prosecutor said Mr Koller tried to fend Hawke off with a gas bottle but he either dropped it or it was knocked out of his hands, and rejected the suggestion the victim was also swinging a screwdriver.

It is the second time Hawke has been found guilty of the murder, having previously successfully appealed against his original conviction.

He will face a sentencing hearing on March 28.